钢筋混凝土受弯构件正截面疲劳性能数值模拟

Numerical simulation of fatigue performance of reinforced concrete flexural components

为了分析钢筋混凝土受弯构件在疲劳荷载作用下正截面力学性能随着时间不断变化的过程,用条带法数值模拟疲劳破坏的整个过程.在已有的钢筋和混凝土轴心疲劳本构关系基础上,根据粘结应力分布规律推导出平均截面的材料本构关系,运用条带法分析钢筋混凝土受弯构件的疲劳性能,编制程序进行计算,程序计算结果与疲劳试验结果进行比较.数值模拟和试验结果表明:受压区高度及混凝土和钢筋的应变发展呈现两阶段规律,随着疲劳荷载次数的增加混凝土和钢筋的应力、应变发生重分布现象;程序和试验结果吻合较好.用编制的程序分析钢筋混凝土受弯构件的疲劳性能具有一定的精度,可部分代替冗长、昂贵的疲劳试验.

The fiber section method is used to study the constantly changing process of reinforced concrete under flexural fatigue loads. The constitutive properties of average sections was deduced based on the existing constitutive properties of component materials, then the flexural fatigue performance of reinforced concrete was presented by fiber section method and was simulated by a computer program. The results of numerical simulations and tests indicate that the development of each fiber＇s stress and strain is divided into two phases; the stress and strain redistribution on cross section of reinforced concrete flexural components under cyclic loads are presented. The curves of xc - n, εcl -n,εs -n based on the simulations are consistent with the test results. The approach and the computer program developed are practical for accelerating the analysis of fatigue behavior of reinforced concrete decks.